Q19: What is a Multikey Index?
When an index is created on a field that contains an array value, MongoDB automatically creates a Multikey Index. It indexes each individual element inside the array separately. Limitations: A compound index can index at most ONE array field.
Key Takeaways
- Automatically created when indexing array fields.
- Cannot construct compound multikey indexes spanning multiple array fields.
Knowledge Check
Can a compound index include two separate array fields in MongoDB?